Rate of Decrease in Neurogenesis Correlates With Longevity

Created on Nov. 18, 2012, 11:38 p.m. by Hevok
& updated by
Hevok
on May 2, 2013, 4:58 p.m.

Neurogenesis is the process of neuron generation from stem cells and progenitors.

New neurons generated within the hippocampus of an adult animal can functionally integrate into the neural circuitry [Kee et al., 2007; van Praag et al., 2002]. The dental gyrus size does not increase with age and remains fairly constant [Ben Abdallah et al., 2010]. Age has a large effect on neurogenesis. Neurogenesis decreases dramatically at old age [Kuhn et al., 1996]. The major decline in neuronal cell generation appears to occur before middle age, indicating that it represents a critical turning period of adult hippocompal neurogenesis [Wu et al., 2008]. Neurogenesis is suggested to peaks at puberty and this might be related to the transition from juvenile to adult behaviour [Amrein and Lipp, 2009].

Among seven different species, the rate of decrease (which appears to be exponential) of neurogenesis correlates with species longevity, but not body mass nor basal metabolic rate. This means longer-lived species have a slower rate of decline in proliferation and neurogenesis [21621300].

Of the total number of cells added to the dentate gyrus postnatally, 69% of these will be added before adulthood, and only 31% of cells will be added during adulthood. Only 8.5% of new cells will be added from middle age onwards. Therefore, for most of adult life, there is little addition of new cells [21621300].

It seems like that there is no "critical turning point" for neurogenesis, but rather than a smooth decrease over time and there appears little evidence for neurogenesis to peak postnatally [21621300].